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City Spin-out: City Occupational Ltd

Developed by Professor John Barbur from City's Department of Optometry and Visual Sciences, the product provides early detection screening tests that reveal changes in colour vision years before retinopathy can be detected clinically, and so prevention can be introduced.

The Background

John Barbur, Professor of Optics and Visual Science, as a founder of Applied Vision Research Centre (AVRC) at City that studies fundamental mechanisms of vision including fundamental visual processes, ophthalmic and physiological optics, vision care and clinical practice, visual neuroscience and the development of specialised instrumentation with emphasis on clinical applications.

As part of studies on camouflage, the AVRC team discovered the existence of independent visual mechanisms for the processing of luminance contrast noise and colour signals. This investigation led to the development of the Colour Assessment and Diagnosis (CAD).

The Challenge

For a large number of professions good eyesight, and particularly, colour vision is critical.

Conventional colour screening tests are employed to screen for congenital red-green (RG) colour deficiency. These tests exhibit large variability and cannot be used to diagnose the class of deficiency or to quantify accurately the severity of colour vision loss. In some professions, such as air traffic control, the more extensive use of colour signals and colour displays also requires normal yellow-blue (YB) colour vision.

Consequently, in the past, pilot, train driver and fire fighter applicants often failed certification requirements because of congenital colour deficiency, even when the applicants were potentially able to carry out the most visually-demanding, colour-related tasks with the same accuracy as subjects with normal colour vision.

The Solution

The CAD test provides a far more detailed and accurate assessment of a person’s colour vision than was previously possible. It establishes whether a person’s red-green and yellow-blue colour vision falls within the normal range and detects and quantifies the severity of any form of colour vision loss.

Results showed that many people with minimal colour deficiency are able to perform visually-demanding, safety critical tasks just as well as those with normal colour vision.

Today the test is used routinely within world-wide aviation authorities, Transport for London and many government departments as well as by research establishments, hospitals and practicing optometrists.

To commercialise the CAD test and other advanced vision and optometric tests for use within occupational and clinical environments, Professor Barbur has set up City Occupational Ltd.

Medical applications of the CAD test include early detection of retinal disease such as diabetic retinopathy and age-related macular degeneration. The latter is the most common cause of blindness in the adult population in the UK.